824 Transactions.—Zoology, 
C. sicotor, Schmarda, l.c., p. 21, pl. 20, f. 169. Quat., le., I., p. 477. 
Segments 50; body rounded, attenuated behind, greyish-yellow, anterior 
portion blue; the whole surface covered with a hyaline jelly ; upper bundles 
of bristles 4-haired ; the lower with hooked seta. 
Genus Siphonostomum, Grube. 
Head distinct; body naked, attenuated behind ; feet with simple bristles 
on both feet. 
B. antarcticum, Baird, P.L.S., XI., p. 95. 
Sete surrounding the head numerous, very short and fine; branchism 
short, numerous; body covered with an enveloping substance like that of 
most of the known species (shaggy). Sete of the inferior ramus of feet 
single, crooked or hooked at the point, and of nearly a black colour. 
Colour of body varying from a very dark to a light brown, and of a trans- 
parent look. Length of longest specimen nearly three inches. 
Family HERMELLIDÆ. 
Tubiculous; segments of two or three kinds, the hinder thread-like 
with no appendages ; head lobes fleshy, with a circlet of yellow pales on 
the prostomial border, which acts as an operculum; tube built up of 
cemented shells. 
Genus Pallasia, Quatrefages. 
Tentacles joined upon the upper face; operculum formed by two con- 
centric rows of sete ; body divided into three regions. 
P. quapricornis, Schmarda, l.c., p. 25, pl. 20, f. 174 (Hermella). Quat., l.c., 
., p. 924. 
Body reddish-yellow ; head and branchie violet; dorsal branchis blue; 
papille short; external pales aculeate at the sides; internal geniculate, 
aculeate; occipital spines four. : 
Family TEREBELLIDA. 
Inhabiting soft, fragile tubes; body with two distinct regions; head 
without pales and lobes, but with large, moveable, ciliated, branchis, 
serving as touch- and prehensile-organs. 
Genus Terebella, Linneus. 
Three pairs of arborescent branchiæ. 
T. puaciostoma, Schmarda, l.c., p. 41, pl. 24, f. 196. Quat., l.c., IT., p. 366. 
Body reddish-yellow ; cephalic branchis pale, short; laterals cinnabar- 
red, short; pinnule in the last segment; mouth transverse. 
T. HETEROBRANCHIA, Schmarda, l.c., p. 42, pl. 94, f. 197. Quat., le., IL., p. 966. 
Body yellowish-grey ; cephalic branchiw clear; first lateral branchia, 
consisting of many equal branches, the others with one branch longer; 
mouth obsolete quadrangular ; pinnule, 
